Standard frame construction is used in virtually all residential and related construction in the United States, and in many other places throughout the world. This method of construction includes a wooden or steel framework of studs covered with a light sheathing of foam, light fiberboard or plywood, Celotex™, or any number of other light sheathing or substrate materials. Normally, heavy-duty fiberboard or plywood is not used throughout a frame construction due to the cost. Further, it has been found far more desirable to use a light-weight sheathing material that has some insulating or even waterproofing value. In most external wall systems some type of siding material is applied over the sheathing to provide water resistance and decorative features.
Sometimes the sheathing or substrate is of wood, and has substantial structural value. In other cases, the sheathing can be low-gauge vinyl supported by a foam backing, to obtain improved insulating properties, but having little structural value. The same types of materials can also be used for the overlying siding. In many cases, neither the siding nor the underlying sheathing is separately capable of supporting a fixture to be mounted on the exterior wall. Consequently, standard frame construction very often requires that both the sheathing and the siding be used in conjunction to support any fixtures to be added to the wall. This is especially important when apertures must be formed in both the substrate and the siding to accommodate a fixture, but which weakens the wall. If the substrate and siding can't support the fixture it must be moved so as to be supported by a stud, or other more substantial portion of the wall.
As a result, the building industry has adopted a number of mounting blocks that utilize the combined strength of both the siding and the underlying substrate or sheathing. Conventionally, this is done by having a lower mounting frame attached, around an aperture (accommodating the fixture to be mounted), and directly attached to the sheathing. A second or upper mounting frame is then connected to the already fixed lower mounting frame, which is attached to the sheathing. Finally, there is a holding piece (or pieces) which attaches either to the upper frame (fixture support) or the lower mounting frame (in some cases both), to hold the siding and to utilize the structural capability of the siding around the overall mounting block. By placing the framework around the aperture in the wall, and firmly interlocking all three of the mounting frame pieces, a moderately stable mounting support for a fixture can be effected, even on a relatively flimsy wall.
However, using conventional mounting blocks, this process has not always been easy to carry out. In many traditional arrangements, three (or more) different pieces must be fit together, along with the fixture to be supported. Consequently, the process can be extremely awkward, especially if unskilled labor is employed, or adverse conditions ensue.
Another problem, even for highly skilled workers, is the fact that conventional mounting blocks normally come in three separate pieces, often with separate connecting devices for each piece. Under the often-chaotic conditions of construction sites, pieces of the mounting blocks, especially the connectors, can be misplaced or lost. This results in delays or other difficulties, and often leads to the expedient of ordering redundant mounting blocks just to make certain that a full kit is available when needed.
This problem has been addressed in part by arrangements in which two of the three components are temporarily attached together. However, there have been difficulties with such arrangements since sometimes the attached components must be separated for one to be mounted, and then reattached to each other. This often leads to breakage.
In some arrangements, two of the components (lower frame and fixture support structure) are formed as one piece, alleviating some of the aforementioned difficulties. However, the upper holding piece which is used to hold the surrounding siding, is usually a separate piece in conventional mounting block designs. Otherwise, it would be very difficult to position and connect the holding piece to the wall using conventional mounting blocks. Unfortunately, this upper holding piece can be lost. In some cases, even if the upper holding piece is not lost, its connectors can be, thereby compromising the overall mounting block.
This drawback has been addressed in U.S. patent application Ser. No. 10/435,258, filed May 9, 2003, by the same inventor and incorporated herein by reference. In this arrangement, the pieces used for holding the siding are attached to a cap-like structure support that is used to support the fixture and has mounting flanges to attach to the substrate or underlayment of the wall. This mounting block is used by cutting away the siding around the aperture through which the fixture will pass through the substrate of the wall. The holding structures are arranged as two rotate able pieces that are permanently attached to the rest of the mounting block. When the mounting block is put in place, the holding pieces rotate opposite each other over the surrounding siding. The subject mounting block is easy to handle and to install. The rotating holding pieces provide a convenient handle for shifting and positioning the entire mounting block. The rotating holding pieces can lock into place around the support structure of the mounting block. The permanent attachment keeps the holding pieces from being lost, or otherwise separated from the rest of the mounting block.
While the overall structure and operation of the aforementioned subject mounting block is generally superior in all respects, there are some disadvantages that have been discovered. Under normal, expected usage, the plastic hinges of the subject mounting block are not at risk. However, as is so often the case on a construction site, abuse can occur and the hinges can break. Likewise, the connections between the rotating holding pieces and the rest of the mounting block can also be broken, creating a separation that might be very difficult to repair. Even if repair is possible, there is the possibility of water working its way past the water tight seals of the mounting block and into the vulnerable, underlying wall.
There are other drawbacks to this design. For example, the plastic hinges can be warped by heat, like any plastic mounting block. Further, the rotation of the holding pieced does not permit an optimum fit for locking purposes, even though some variation of siding thicknesses can be accommodated for this particular design. As with any plastic design, general warping of the overall structure of the mounting block may lead to the intrusion of water at various points through and around the mounting block. Also, as is the case at any construction site, less than precise measurements may result in situations that cannot be accommodated by a particular mounting block. This would result in a questionable connection the mounting block and the building, compromising both the fixture and the surrounding siding.
Another major drawback of the conventional mounting block art is that a wide range of different fixtures must be accommodated. It has become standard use in the construction industry that different types of fixtures require different sizes and types of mounting blocks. Consequently, a wide range of drilling patterns and parts are necessary. On large construction sites with substantial numbers of different mounting blocks, the complexity associated with multiple installations of different types of blocks can become so great as to be debilitating. This is especially true when parts for different fixture sizes and types bear a close resemblance to each other.
A further drawback with much of the conventional mounting block art is that very often substantial numbers of parts are involved in the mounting of each fixture (for example: fixture, decorative cover plate, mounting block base, electrical box, siding flange and/or multiple cover plates for the electrical box and mounting block). These multiple parts require multiple connections to each other so that there is very often a chain of connections, some of which may not be particularly secure. As a result, even if the installation takes places properly, the overall assembly may not be particularly secure. This can be both expensive and dangerous with electrical fixtures.
Accordingly, there is a substantial need for an improved wall-mounting block that overcomes the difficulties of the conventional mounting blocks. In particular, such an improved mounting block would alleviate the problems of lost parts, and facilitate easy installation. Also, an improved mounting block would provide for varying thicknesses of siding and sheathing while maintaining substantial resistance to water intrusion. The improved mounting block system would limit the number of different parts required, and would provide for very stable connections to secure the fixture being mounted to the block. This is especially important when mounting electrical fixtures in conjunction with electrical boxes.